1. Field of the Invention
This invention relates to a computer interface apparatus, which is to be located between a computer, such as a personal computer, and a stencil printer and connects them with each other such that a print may be formed by the stencil printer in accordance with print data having been formed by the computer.
2. Description of the Prior Art
In cases where prints are to be formed by a printer in accordance with data (text data, image data, or the like) having been formed by a personal computer, a printer driver, which has been installed in the personal computer in accordance with resolution of the printer, has heretofore converted the text data, or the like, which has been formed by the personal computer, in accordance with a printing instruction given by application software functions, such that the converted data matching with the resolution of the printer may be obtained. Print data has heretofore been formed in this manner. (Such print data is referred to as the "resolution-dependent type of print data.") Also, recently, print data, which has been fed from a personal computer, is often used directly for forming prints by a stencil printer.
FIG. 7 is a block diagram showing a system comprising a personal computer, a computer interface apparatus, and a personal computer, in which a print is formed by the stencil printer in accordance with print data having been fed from the personal computer. As illustrated in FIG. 7, the system comprises a personal computer 1, which is an example of the computer, a stencil printer 3, and a computer interface apparatus 2, which is connected between the personal computer 1 and the stencil printer 3. When the print data is inputted from the personal computer 1 into the computer interface apparatus 2, the computer interface apparatus 2 forms page output data for the stencil printer in accordance with address data, raster image data, page discharging data, and the like, which are contained in the print data having been received from the personal computer 1. Thereafter, the computer interface apparatus 2 feeds the page output data into the stencil printer 3. The stencil printer 3 carries out a printing operation in accordance with the page output data, which has been received from the computer interface apparatus 2. Also, by connecting the computer interface apparatus 2 with a modem (modulator-demodulator) 5, print data, which is fed out from a personal computer 4 located at a remote site, may be utilized for forming a print with the stencil printer 3 via a modem 6.
Ordinarily, in cases where a print is to be formed by a stencil printer in accordance with the resolution-dependent type of print data, which has been formed by a personal computer, print data, which conform to the resolution of the stencil printer connected to the computer interface apparatus, are formed on the side of the personal computer, and resolution converting functions are not required in the computer interface apparatus. Therefore, in cases where one of stencil printers having different levels of resolution, e.g. 300 dpi, 400 dpi, and 600 dpi, is connected to the computer interface apparatus, if the resolution of the stencil printer connected to the computer interface apparatus does not coincide with the resolution assumed by the personal computer, some problems occur in that the image information represented by the print data cannot be printed at correct printing positions, and image expansion or contraction and image collapse will occur on the print.
Also, in cases where print data can be formed only with a predetermined resolution depending on a personal computer and only one kind of stencil printer is available, a conversion of resolution, which converts the resolution of the page output data to the resolution of the stencil printer is carried out on the computer interface apparatus. However, with such a technique, if another stencil printer having another resolution is connected to the computer interface apparatus, image expansion or contraction and image collapse will occur on the print, and normal printing cannot be carried out.
Further, in cases where data transfer is carried out via modems, an operator, who is located at the remote site near the modem and the personal computer, cannot discriminate the type of the stencil printer connected to the computer interface apparatus. Therefore, it is difficult for the operator, who is located at the remote site, to recognize the resolution of the stencil printer connected to the computer interface apparatus. Thus the problems have heretofore been encountered in that the print data, which is transferred from the personal computer, cannot always be obtained as the print data conforming to the resolution of the stencil printer.